How much does a 1.00 to 1.49ct G SI1 natural cushion diamond cost?

As of November 2026, 1.00 to 1.49ct G SI1 natural cushion diamonds typically cost £1,104 GBP to £3,426 GBP, with a median price of £1,954 GBP. There are currently 533 diamonds matching this specification available across retailers.

Where can I find the best price on a G SI1 cushion diamond?

About 34% of these diamonds are available at multiple retailers, with an average price spread of 60%. A comparison tool like Carat Hunter lets you see all the prices side by side.

1.00 to 1.49ct G SI1 Natural Cushion

Quick answer

As of November 2026, there are 533 natural cushion diamonds with G colour and SI1 clarity in the 1.00 to 1.49ct range available across retailers worldwide. Prices typically run £1,104 GBP to £3,426 GBP, with a median of £1,954 GBP. At least 62 retailers stock this exact specification, and 34% of the stones appear at more than one of them, with an average price spread of 60%. Half of all listings fall between £1,417 GBP and £2,566 GBP per carat. The same specification in lab grown form lists at a median of about £361 GBP per carat. Over the last 30 days the median price moved -1.0% and the number of listings moved +6.6%.

Three of the best scored stones at this specification right now:

Caratlytics Diamond Price Index, September 2026: natural diamonds at 2,335 USD per carat and lab-grown at 443 USD per carat, a natural to lab ratio of 5.3 to 1. Cushion natural stones in the index: 2,948 USD per carat, +1.7% month on month. See the full index release

Figures come from current listings across more than 100 retailers and refresh daily. The index is a monthly release.

Last updated: November 2026

Available

533

Lowest Price

£789 GBP

Highest Price

£7,916 GBP

Average Price

£2,164 GBP